Update the XBlock version to fix save bugs
give some debug message regarding why export might fail
switch the notification to be a prompt and allow for the user to go to the edit unit page which contains the module in error. Otherwise, present the raw exception message and allow user to go to the course outline page.
handle exceptions inside the outer exception handling
implement PR feedback
get_item -> get_instance
need to filter out non-own metadata. Also we need to clone draft content
update some unit tests on clone_course
add more testing. Assert that metadata is properly cloned and that draft content is cloned as well
address PR feedback
Merge pull request #609 from edx/fix/cdodge/clone-course-needs-to-save-only-own-metadata

[STUD-608] django-admin clone_course needs to properly copy metadata as well as draft content
Making it possible to tab to captions.

When a VideoAlpha is present on the page, if the user tries to tab through out the entire page, eventually he will land on the VideoAlpha controls. The tab index order has been set up so that all control receive focus eventually in the order from left to right. When a control receives focus, it is hilighted. The last tab focuses the captions dialog. When the captions dialog has focus, the Up and Down arrows can scroll it up and down.
Fixed styling for volume button.

For some reason the "muted" icon was not showing. Styles have been corrected.Now on focus background color is also simplified for div
.volume control.
Removing JavaScript qTip tooltips.

Because sometimes the tooltips generated by qTip get in the way, and the controls becomes
not responsive, it was decided to use standard title attributes for tips.

Also along the way, an error was discoevered in Jasmine tests. It was fixed, but that test is
failing so it was marked specifically to be skipped when all VideoAlpha tests run.
Fixed failing test for VideoAlpha caption heiht.

It turns out that there was wrong invocation of toBeCloseTo() function. Most likely a typo.
Updated the readme.
Made it so that keyboard also prolongs auto hiding of controls.
Fixed bug dealing with empty subtitles Url string.

Now when subs parameter is empty or the YouTube IDs are not specified,
captions will not try to fetch non-existent file.
Styling improvements.
Volume and speeds dialogs are fully extended.

When the controls receive focus not via mouse click or mouse hover, their appropriate
slider and selection menu are fully extended and shown to the user.
Replaced Video with VideoAlpha.

Now all Video tags and VideoAlpha tags will be handled by VideoAlpha.